#include<stdlib.h>
#include<pthread.h>
#include<sys/socket.h>
#include<sys/types.h>       //pthread_t , pthread_attr_t and so on.
#include<stdio.h>
#include<netinet/in.h>      //structure sockaddr_in
#include<arpa/inet.h>       //Func : htonl; htons; ntohl; ntohs
#include<assert.h>          //Func :assert
#include<string.h>          //Func :memset bzero
#include<unistd.h>          //Func :close,write,read
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
#define MAX_CONN_LIMIT 512     //MAX connection limit

static void Data_handle(void * sock_fd);   //Only can be seen in the file
int CountWordsOfEuropeanTxtFile(char *szFileName);
int CountWordsInOneLine(const char *szLine);

int main()
{
    int sockfd_server;
    int sockfd;
    int fd_temp;
    struct sockaddr_in s_addr_in;
    struct sockaddr_in s_addr_client;
    int client_length;

    sockfd_server = socket(AF_INET,SOCK_STREAM,0);  //ipv4,TCP
    assert(sockfd_server != -1);

    //before bind(), set the attr of structure sockaddr.
    memset(&s_addr_in,0,sizeof(s_addr_in));
    s_addr_in.sin_family = AF_INET;
    s_addr_in.sin_addr.s_addr = htonl(INADDR_ANY);  //trans addr from uint32_t host byte order to network byte order.
    s_addr_in.sin_port = htons(SOCK_PORT);          //trans port from uint16_t host byte order to network byte order.
    fd_temp = bind(sockfd_server,(const struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
    if(fd_temp == -1)
    {
        fprintf(stderr,"bind error!\n");
        exit(1);
    }

    fd_temp = listen(sockfd_server,MAX_CONN_LIMIT);
    if(fd_temp == -1)
    {
        fprintf(stderr,"listen error!\n");
        exit(1);
    }

    while(1)
    {
        printf("waiting for new connection...\n");
        pthread_t thread_id;
        client_length = sizeof(s_addr_client);

        //Block here. Until server accpets a new connection.
        sockfd = accept(sockfd_server,(struct sockaddr * restrict)(&s_addr_client),(socklen_t *)(&client_length));
        if(sockfd == -1)
        {
            fprintf(stderr,"Accept error!\n");
            continue;                               //ignore current socket ,continue while loop.
        }
        printf("A new connection occurs!\n");
        if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
        {
            fprintf(stderr,"pthread_create error!\n");
            break;                                  //break while loop
        }
    }

    //Clear
    int ret = shutdown(sockfd_server,SHUT_WR); //shut down the all or part of a full-duplex connection.
    assert(ret != -1);

    printf("Server shuts down\n");
    return 0;
}

static void Data_handle(void * sock_fd)
{
    int fd = *((int *)sock_fd);
    int i_recvBytes;
    char data_recv[BUFFER_LENGTH];
    const char * data_send = "Server has received your request!\n";

    while(1)
    {
        printf("waiting for file_name...\n");
        //Reset data.
        memset(data_recv,0,BUFFER_LENGTH);

        i_recvBytes = read(fd,data_recv,BUFFER_LENGTH);
        if(i_recvBytes == 0)
        {
            printf("Maybe the client has closed\n");
            break;
        }
        if(i_recvBytes == -1)
        {
            fprintf(stderr,"read error!\n");
            break;
        }
        if(strcmp(data_recv,"quit")==0)
        {
            printf("Quit command!\n");
            break;                           //Break the while loop.
        }
        printf("read from client : %s\n",data_recv);
		
	char buffer[BUFFER_LENGTH];
	int count=0;
	bzero(buffer, BUFFER_LENGTH);
	count = CountWordsOfEuropeanTxtFile(data_recv);
	sprintf(buffer,"%d", count);
        send(fd, buffer, sizeof(buffer), 0);


        if(write(fd,data_send,strlen(data_send)) == -1)
        {
            break;
        }
    }

    //Clear
    printf("terminating current client_connection...\n");
    close(fd);            //close a file descriptor.
    pthread_exit(NULL);   //terminate calling thread!
}

int CountWordsOfEuropeanTxtFile(char *szFileName)
{
	int nWords = 0;//词计数变量，初始值为0
	FILE *fp; //文件指针
	char carrBuffer[1024];//每行字符缓冲，每行最多1024个字符

	//打开文件
	if ((fp = fopen(szFileName,  "r")) == NULL)
	{
		return -1;	//文件打开不成功是返回-1
	}

	while (!feof(fp))//如果没有读到文件末尾 
	{
		//从文件中读一行
		if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
			//统计每行词数
			nWords += CountWordsInOneLine(carrBuffer);
	}

	//关闭文件
	fclose(fp);

	return nWords;
}


int CountWordsInOneLine(const char *szLine)
{
	int nWords = 0;
	int i=0;
	for (;i<strlen(szLine);i++)
	{
		if (*(szLine+i)!=' ')
		{
			nWords++;
			while ((*(szLine+i)!=' ')&&(*(szLine+i)!='\0'))
			{
				i++;
			}
		}

	}
			//printf("%d\t",nWords);
	
	return nWords;
}
